You asked for opinions, so.... here we go
It feels like you lit most shots failrly from the front, which causes some issues...
1: pose is alright, although it would have looked more relaxed if she would have leaned on the back of chair with her right arm I think. Also she could have used a bit more light, her hair is almost swallowed by the darkness (unless that was intended?)
2: pose is ok, nice touch with the hat....but woah, way too bright in the foreground. Facial features are almost completely gone. The idea of high key is that the background is completely blown out white, but it's so as to emphasize the contrast to the foreground, to show every hair clearly etc. So the foreground still needs to be evenly lit. Not sure if you used a photoshop filter on the image, maybe you just went overboard with that?
3: quite nice, again a bit overly bright and from the front, but a good focus and nice and clean background. Not sure I like the crop, I'd probably have given her a bit more space at the bottom and less at the top.
4: Again I think the light is the problem here on an otherwise good shot. Not soft enough and too frontal.
How did you set up your lights? It feels like the flash was on camera? Did you use a diffusor? I would strongly suggest to get a separate lightstand and some means to fire the flash remotely (cable would probably be the cheapest? don't know. I use CLS) and definitely get a cheap softbox or umbrella. "Flash in the pan" is selling some good ones for cheap here in the forums. Will improve the shots immediately for little money!
Michael